99 





Donations to the Library. 



From Lieut. Maury, a full series of his Wind 

 and Weather Charts. 



From the Boston Society of Natural History, 

 their Proceedings, vol. 6, pp. 49-64. 



From the Natural History Society of Montre- 

 al, their Twenty-eighth Annual Report. 



A Circular, from the California Society of 

 Natural History, Stockton. 



American Journal of Science, No. 68, from 

 the Editors. 



From Air. T. F. Moss, eleven Nos. of La Sci- 

 ence. 



Mr. Moss deposited Paleontologie et Geologie, 

 three volumes ; also, Precis d' Analyse Chimique. 



Capt. Russell deposited a volume of Records 

 of the Mission of San Diego, in Spanish, dating 

 back to A. D. 1770. 



Letters were read from M. Rene Lcnormand, 

 Mr. W. H. Pease and Mr. W. P. Blake. 



The thanks of the Academy were voted to the 

 Editors of the Pacific Sentinel, Santa Cruz, for a 

 file of their paper furnished regularly for several 

 months past. 



The Recording Secretary was requested to 

 communicate to Mr. Joseph C. Palmer the thanks 

 of the Academy, for his very liberal donation of 

 the rent of the Academy rooms for the ensuing 

 year. 



Dr. Trask read the following paper 



ON SOME NEW MICROSCOPIC ORGANISMS. 



During the summer of 1855, while in the vi- 

 cinity of Santa Barbara, engaged in the examin- 

 ation of several species of marine algae to which 

 many zoophytes were attached, I accidentally 

 met with the forms which constitute the subject 

 of this paper. Since that time, further observa- 

 tions have been made, and examinations for 

 their presence with more success than was at 

 first anticipated. 



The striated appearance of these minute or- 

 ganisms led to the belief at first that the lorica 

 belonging to them was silicious, but the appli- 

 cation of chemical agents has shown this not to 

 be the case, for it is entirely destroyed by di- 

 gestion in strong nitric acid, continued for a 

 considerable length of time. 



In the normal state the forms are brittle, and 

 easily broken under a compressor, but after di- 

 gestion in nitric acid the lorica becomes soft and 

 flexible, losing none of its configuration except 

 on the application of mechanical means. In 

 this particular they comport themselves with the 

 calcareous portions of animal structures. The 

 striated appearance which they present is (by 

 the above means) found to consist of septa, placed 

 transversely across a longitudinal canal entend- 

 ing the entire length of the organism, and so 

 far as present observations have extended, they 

 present the peculiar features of being solid, for 

 by compression they have been extruded from 

 the canal, and retain their forms when thus 



Troc. Cal. Acad. Nat. Sci. 



free, the canal collapsing where the extrusion of 

 the septa has taken place. 



In view of the above facts it will be necessary 

 to place these minute organisms among the fam- 

 ily of crustaceas, their form and inorganic 

 structure, with their configuration seeming to 

 warrant this, more properly perhaps than among 

 the zoophytes, or diatoms. 



The mandibular process on the anterior end 

 simulates in some particulars the vibracular 

 organs of the zoophytes, but what particular 

 office it performs in their economy is yet unde- 

 termined, having never had an opportunity of 

 examining their movements when freshly col- 

 lected, with instruments of sufficient power. The 

 materials from which they have been obtained 

 have laid for months, in most cases, before op- 

 portunity offered for their investigation. 



The mandibular process is placed on a mova- 

 ble joint, and has the appearance of being at- 

 tached and capable of motion through the agency 

 of muscular filaments passing within the outer 

 covering of the animal ; by digestion in acid it 

 is often very soon detached from the head of the 

 styliform body to which it belongs, but when in 

 place it has considerable lattitude of motion. 

 The figures are drawn with the camera-lucida 

 and a microscope by Oberhauser. 



These forms are certainly most singular, parta- 

 king as they do, the appearance both of animal 

 and vegetable forms. Certain it is, they belong 

 to no genus at present known, or with which we 

 are at present acquainted, and under this view 

 we shall place them in a new genus, with the 

 following definition : 



Leptosiagon — Trask — Nov. Gen. 

 Lorica membrano-calcareous, styliform; straight 

 or curved, having a central canal, which is di- 

 vided by transverse septa its entire length ; an- 

 terior extremity furcate, more or less enlarged, 

 and traversed by one or more bands or ribs raised 

 above the surface, and armed Avith a movable 

 mandibular process more or less denticulated ; 

 posterior extremity either acute, rounded or ca- 

 pitate ; body rounded, smooth, more or less com- 

 pressed. 



Leptosiagon gracilis ng. ns. — Trask — Plate 6, 

 fig. 1. — Lorica straight, smooth, compressed, an- 

 terior extremity furcate, forming two somewhat 

 unequal beaks, and armed with a long smoothly 

 curved mandible, having about sixteen fine acute 

 denticulations on one side, its anterior end 

 acutely terminated, broadest part of mandible 

 about one-fifth greater than the body below ; 

 posterior extremity subcapitate and rounded, 

 shows a terminal orifice to the central canal. — 

 Transverse section ovate. Length of mandible 

 contained about five and one-half times in the 

 length of the body. Breadth of body about 

 l-80th its length. Mag. 550 diameters. 



On algae attached to fish cars — Santa Barbara. 



This species is adopted as typical of the genus, 

 for the reason that it appears most plentiful when 

 compared to the others, was the first met with 

 and is beautifully marked, and symmetrical. 



L. occidcntalis. ng. ns. — Trask — Plate 

 6, fig. 2 — Lorica straight, smooth, anterior ex- 

 tremity equally furcate, and terminated on the 

 ventral side by a somewhat bluntly rounded pro- 

 cess, with a smaller one on the dorsal side, arm- 



